1. Field of the Invention
The present invention relates to an interengageable fuel flange and filler tube for fuel tanks. More specifically, the present invention relates to an interengageable plastic fuel flange and filler tube combination which are engageable in a snap fit relation.
2. Discussion of the Related Art
Fuel tanks for transportation purposes have recently been designed from plastic materials because of their ability to be easily fabricated and because of their light weight nature.
In automotive uses in particular, the plastic fuel tank has an opening which is surrounded by a fuel flange. Into the fuel flange is received a filler tube which directs the fuel through the fuel flange and into the fuel tank. Attached on the outside of the fuel flange is a hose that is held in place on the fuel flange by a clamp mechanism and this hose connects up with the fuel door on the vehicle, thereby allowing fuel to be pumped to the tank.
In the Past, the plastic fuel tank included a rubber grommet in its opening and a metal tube press fit therein. This arrangement was modified so that a plastic fuel flange (containing a metal filler tube) could be heat welded to the plastic tank. Prior to welding the plastic fuel flange to the tank, the metal filler tube was assembled therein. The process for assembling the metal filler tube in the fuel flange included i) injection molding the plastic fuel flange and ii) jamming the metal filler tube into an abutting relation with the fuel flange, immediately after it comes out of the injection molder. The plastic fuel flange then cooled and caused a shrink fit between the two parts.
Static electricity may build on plastic parts from the flow of fuel over the plastic. Metal parts in direct contact with the plastic are generally grounded to the vehicle frame. Currently, this is done by contacting the edge of the metal filler tube with the conductive rubber tube that is grounded to the body. Thus, if any static charge develops, the charge is grounded to the body. This concern would not be an issue if metal was not used in the fuel fill system.
Metal filler tubes also have further problems. If it is necessary to change the length of the metal filler tube, the change in tooling is expensive. The metal parts are also expensive. Further, an untreated metal filler tube may rust in the system. It would, therefore, be advantageous to switch from a metal filler tube to a material which would not have the above-mentioned disadvantages. One material which has been considered as a substitute for a metal filler tube is plastic. Another, perhaps most important, reason why Plastic has never been used is because it was not known how to retain the plastic filler tube in the fuel flange and how to prevent it from moving axially relative thereto.